Vendor things

third-party/vendor/png/benches/decoder.rs

@@ -0,0 +1,81 @@
+use std::fs;
+
+use criterion::{
+    criterion_group, criterion_main, measurement::WallTime, BenchmarkGroup, Criterion, Throughput,
+};
+use png::{Decoder, Reader, Transformations};
+
+#[path = "../src/test_utils.rs"]
+mod test_utils;
+
+fn load_all(c: &mut Criterion) {
+    let mut g = c.benchmark_group("decode");
+    for entry in fs::read_dir("tests/benches/").unwrap().flatten() {
+        match entry.path().extension() {
+            Some(st) if st == "png" => {}
+            _ => continue,
+        }
+
+        let data = fs::read(entry.path()).unwrap();
+        bench_file(&mut g, data, entry.file_name().into_string().unwrap());
+    }
+    g.finish();
+
+    // Small IDATS
+    let mut g = c.benchmark_group("generated-noncompressed-4k-idat");
+    bench_noncompressed_png(&mut g, 8, 4096); // 256 B
+    bench_noncompressed_png(&mut g, 128, 4096); // 64 KB
+    bench_noncompressed_png(&mut g, 2048, 4096); // 16 MB
+    bench_noncompressed_png(&mut g, 12288, 4096); // 576 MB
+    g.finish();
+
+    // Normal IDATS
+    let mut g = c.benchmark_group("generated-noncompressed-64k-idat");
+    bench_noncompressed_png(&mut g, 128, 65536); // 64 KB
+    bench_noncompressed_png(&mut g, 2048, 65536); // 16 MB
+    bench_noncompressed_png(&mut g, 12288, 65536); // 576 MB
+    g.finish();
+
+    // Large IDATS
+    let mut g = c.benchmark_group("generated-noncompressed-2g-idat");
+    bench_noncompressed_png(&mut g, 2048, 0x7fffffff); // 16 MB
+    bench_noncompressed_png(&mut g, 12288, 0x7fffffff); // 576 MB
+    g.finish();
+}
+
+criterion_group! {benches, load_all}
+criterion_main!(benches);
+
+fn bench_noncompressed_png(g: &mut BenchmarkGroup<WallTime>, size: u32, idat_bytes: usize) {
+    let mut data = Vec::new();
+    test_utils::write_noncompressed_png(&mut data, size, idat_bytes);
+    bench_file(g, data, format!("{size}x{size}.png"));
+}
+
+fn bench_file(g: &mut BenchmarkGroup<WallTime>, data: Vec<u8>, name: String) {
+    if data.len() > 1_000_000 {
+        g.sample_size(10);
+    }
+
+    fn create_reader(data: &[u8]) -> Reader<&[u8]> {
+        let mut decoder = Decoder::new(data);
+
+        // Cover default transformations used by the `image` crate when constructing
+        // `image::codecs::png::PngDecoder`.
+        decoder.set_transformations(Transformations::EXPAND);
+
+        decoder.read_info().unwrap()
+    }
+
+    let mut reader = create_reader(data.as_slice());
+    let mut image = vec![0; reader.output_buffer_size()];
+    let info = reader.next_frame(&mut image).unwrap();
+
+    g.throughput(Throughput::Bytes(info.buffer_size() as u64));
+    g.bench_with_input(name, &data, |b, data| {
+        b.iter(|| {
+            let mut reader = create_reader(data.as_slice());
+            reader.next_frame(&mut image).unwrap();
+        })
+    });
+}